USB Keyboard stops working after boot; can't ALT-SHIFT-S

Disable Secure Lockdown from 2nd Admin Account – If you want to disable Secure Lockdown from a 2nd
Windows Administrator account on the locked down system, add the “HKEY_LOCAL_MACHINE
\Software\Inteset\SecureLockdown_v2” Windows Registry String Value (REG_SZ) of
"SLCommandVerb=disable_secure_lockdown”

Doesn't this need a Name? I'm assuming the "SLCommandVerb=disable_secure_lockdown” goes in the Value??

The name is "SLCommandVerb". The value is "disable_secure_lockdown”

Install Secure Lockdown on the accessible account, then enable it, then disable it. The problem is that the Machine Level settings from the previous locked down account still remain. Enabling, then disabling Secure Lockdown will reset those Machine Level settings.

If I enable it on this account and I don't have a keyboard, how will I disable it??

Make sure the System Lockdown > Machine Level > No New USB Devices option is disabled before enabling Secure Lockdown.

OK, I did all that. Then deactivated and uninstalled. Most of stuff has come back but I still can't access any USB devices on this machine. It makes a noise when I plug them in but that's it. Which means I can't use it or try and reinstall.

Try cleaning out the device drivers:

I did that. Under "Other Devices" it still says "USB KB- Setup blocked by group policy". I deleted it from Device Manager while it was plugged in and not working, then plugged it in again. Now it works. There should be a BIG Warning symbol next the USB Machine options IMHO.

This is not a typical outcome of using the "No New USB Devices" feature. It's unclear what caused these results on your system.